Prospective Cohort Study to Evaluate Safety/Immunogenicity of Butantan Influenza Vaccine in Healthy Adults/Elderly

Inclusion Criteria: * Healthy adults, male or female aged 18 to 59 * Elderly aged 60 years completed and above * To be available to participate in the study throughout its duration (approximately 21 days) * To have medical indication to be vaccinated against influenza * To demonstrate intention to participate in the study, as documented by signature in the study´s informed consent form. Exclusion Criteria: * Evidence of active neurological, cardiac, pulmonary, hepatic or renal disease as clinical history and/or physical examination (except hypertension under control among the elderly) * Compromised immune system diseases including: HIV, diabetes mellitus, cancer (except basal cell carcinoma) and autoimmune diseases * Behavioral, cognitive or psychiatric disease that in the opinion of the principal investigator or his representative physician, affects the participant ability to understand and cooperate with all study protocol requirements * Abusive usage of alcohol or drugs in the past 12 months that has caused medical, professional or family problems, indicated by clinical history * Known systemic hypersensitivity to eggs or to any component of the vaccine * History of severe adverse reaction after previous administration of an Influenza vaccine within 6 weeks following vaccination * History of Guillain-Barre Syndrome or other demyelinating disease * Diagnosis of asthma with a history of hospitalization in the last six months due to illness * Suspected or confirmed fever in the 3 days prior to vaccination or axillary temperature greater than 37.8 ° C on the day of vaccination * Use of corticosteroids (except topical or nasal) or other immunosuppressive drugs within 42 days before study initiation/baseline. It will be considered immunosuppressive dose of corticosteroids the equivalent to a dose ≥10 mg of prednisone per day for over 14 days * Impaired coagulation due to chronic disease or due to use anticoagulant medication (warfarin or heparin) in the 7 days preceding vaccination * Have received live virus vaccine within 28 days or killed virus vaccine in the last 14 days prior to vaccination, or have a scheduled immunization during the first 21 days after vaccination * Have received influenza vaccine in the past 6 months; * History of asplenia * Have received blood products in the past 6 months, including transfusions or immunoglobulin, or scheduled administration of blood products or immunoglobulin for the first 21 days after vaccination * have a counterindication for Influenza vaccination, including allergy to egg proteins * Use of any investigational product within 42 days before vaccination; * Any other condition that might put in risk the safety/rights of a potential participant or hurdle his/her compliance with this protocol in investigator's opinion or his representative physician.